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Little Dot Tube Amps: Vacuum Tube Rolling Guide - Page 301

post #4501 of 10486
Quote:
Originally Posted by mordy View Post
 

Hi kvtaco 17,

 

When you figured out how to mount it, could you please post pictures -thanks

Oh I will! I have a few Ideas, the problem is how I want to go about the cutting...

post #4502 of 10486

In today's mail, a 1952 Tung Sol 6SN7GT "Mouse Ears" arrived. This tube has two round mica spacers attached to the rectangular top mica and making contact with the glass on each side (“Mouse Ears”). This tube has a good reputation in the 6SN7 community and isn't all that expensive. I gave about $15 with shipping for this one.

 

 

post #4503 of 10486

Here is my present favorite tube - a 6SL7GT Tung Sol tube from 07/57. After cooking for three days straight (don't worry, barely gets warm) it produces bone rattling bass when called upon, and a clear warm detailed musical presentation with a an excellent sound stage. So what's the problem? I can't get myself to remove it and try other tubes that are waiting to burnt in. It's  so nice and engaging that I am just enjoying listening to music and not to the tubes. Yes, i am taking a break.....

 

 

 

 

 

Gibosi was kind enough to send me a link to a great and exhaustive write up about 6SN7 tubes. Some of the things said stated there apply to all NOS tubes and made me change my mind on which tubes are desirable or not.

 

http://www.head-fi.org/t/117677/the-reference-6sn7-thread

 

Even though it is a lot to read, take the time to peruse it - it is worth it!

 

On another note, I went through about 75% of my write up on how to make adapters, with many pictures, descriptions etc. Then my computer crashed (something that does not happen usually) and I lost everything. Seems that there is a problem with the Editor window. Would appreciate if somebody has a tip on writing a post without losing it, which has happened a

few times to me.

post #4504 of 10486
Quote:
Originally Posted by mordy View Post
 

On another note, I went through about 75% of my write up on how to make adapters, with many pictures, descriptions etc. Then my computer crashed (something that does not happen usually) and I lost everything. Seems that there is a problem with the Editor window. Would appreciate if somebody has a tip on writing a post without losing it, which has happened a

few times to me.

 

I have had Head-fi's Editor window freeze on me more than once...... So now, if I plan to write more than just a few lines, I usually compose in Windows Notepad, and when it is ready to go, I then copy and paste into the Head-fi Editor and submit. Cheers.

post #4505 of 10486
Same here with a notepad to web editor posting, I have done that for years and it is a good practice to get into.

Unlike other forums, HF does not save drafts. I was making a post on Icrontic, had quite a few browser windows open when the power blipped and the box reset. Rebooted, went back to Icrontic and hit the draft tab. There was my post all ready to go so I just hit submit. biggrin.gif
post #4506 of 10486

Hi TD,

 

I don't quite understand what I should do not to lose my information - could you give more details - thanks.

post #4507 of 10486

HOW TO MAKE A SOLDERLESS TUBE ADAPTER FOR LITTLE DOT AMPS:

 
 
 
OK, so here are the instructions for making an adapter to use tubes not originally intended for the Little Dot amps. First we need a breadboard:
images?q=tbn:ANd9GcRk2-aU72FYhs5EpkrriCZ_q2Q6XoaP97mKnDHg0V4WcHjc3pgsaQ
Oops, this is not a cooking show! (Could not resist a joke to put you in a good mood to tackle this task) . We need an ELECTRONIC breadboard:
It looks like this:
As you can see, it has 18 screw terminals numbered 1 to 9. Each number on the board corresponds to one pin of the 9 pin tube, and the screw terminals allow you to connect two wires to each pin. Usually you only need one wire. A small flat blade screw driver is all that is needed. The board pictured here costs $24.00 and is US made. Look for
http://www.ebay.com/itm/9-pin-breadboard-prototype-tube-socket-for-DIY-experimenting-/151176364267?pt=Vintage_Electronics_R2&hash=item2332d040eb
  •  
  •  
  •  
 

 

There are other boards available for $7.00 to 15.00. For some reason availability varies, but the cheaper Chinese ones are well made.

This one sells for $15. The one below is Chinese and cost $7.00 but I do not see it on US Ebay right now. Available on European Ebay sites (for more money).

This model requires you to solder in little wires to connect the two little holes that are intended for resistors. Look for

1SET 9pin B9A tube test diy Experiment prototyping pcb for EL84 ECC83 12AX7 ECC8

Next you need two Vector adapters. The best price I have found is from Radiodaze ($5.00 each + shipping approximately $6.00):

images?q=tbn:ANd9GcS3cXf3XwCVQoBdnePm--sL4OtuEfgWfLsYXsr4wFgJZ_jV23Os

http://www.radiodaze.com/vgm_search_result.aspx

Next you need stranded wire 22 AWG. The thickness of the wire is determined by what fits into the hole on the Vector tabs. I scavenged wires from a discarded PC power supply, but most anything will do, but do not use solid wire. At first I used very thin solid 30AWG wire wrap wire, but it had two disadvantages: It was too thin and broke off, and the insulation was also too thin, making it susceptible to electro-magnetic interference. Solid wire is less pliable and will make it difficult to close the Vector adapter.

You need something to strip the wires with, a wire stripper, cutting pliers, scissors or whatever.  9-10 " long pieces of wire is more than enough (need 9 pieces). The end for the breadboard screw terminal should be stripped approximately 2/16 "; the other end for the Vector about 3/8".

The Vectors are clever little devices, but can be very pesky. There is a threaded screw with a nut that goes through the adapter and holds it together. You need to take this screw out to work with the adapter. The nut on the bottom is tiny - make sure that your work surface does not make it disappear when it falls out, which it will. -Just thought of it; a little piece of tape will hold it in place so that you don't lose it.

 

AFTER TAKING OUT THE SCREW DO NOT SEPARATE THE ADAPTER INTO TWO PIECES!!! It will be extremely difficult to put it together. Just pull it apart a little. Use a little rubber band to prevent the pins from pulling out of the bottom piece.

 

 

 

As you can see, the tabs are numbered 1 to 7. Each tab is bent at a right angle, and the tab has a hole in it. Now carefully thread your wire through the appropriate hole. A small needle nose pliers will help. Twist together the end of the wire with the rest of the wire.

 

After the wiring is done, the adapter is pressed together, and the screw with a tiny lock washer on top is inserted from the top. The nut is held in place by a cutout. Tighten gently; overtightening can break the adapter. Believe it or not, this pressure fit of the wires gives better contact than soldering the wires. Make sure that no strands of wire can come into contact with an adjacent wire.

 

 

Insert the corresponding wires into the breadboard and tighten with a small flat blade screwdriver. It may be easier to do one wire at a time and do both ends before pressing together the adapter. After tightening all screws and connections, test all connections by pulling on them. Recheck that all the wires go to the proper places using the diagrams on pages 252, 253 and 275. There are three variations depending on which tube type you use.

 

 

 

 

You may want to put on something on the bottom of the bread board to keep the solder points touching the surface you are putting it on. There are four holes in the breadboard where you could put in screws with nuts to lift it off the surface. I used a little piece of self stick foam i found, maybe from a piece of door insulation.

 

The last two pictures show the screw and nut.

 

 

Here is wiring diagram for a 12AX7 tube:

12AX7
 
9-pin socket           left LD socket        right LD socket
 
1 plate triode 1                5                        
2 grid triode 1                  1
3 cathode triode 1            2
4 heater                                                    3                         
5 heater                                                    3                         
6 plate triode 2                                           5
7 grid triode 2                                             1
8 cathode triode 2                                       2
9                                                              4

 

Just look for screw terminal 1 on the breadboard and connect the wire to the left Vector #5 etc etc. Once you are finished it does not matter which side of the Little Dot amp you plug in the adapters. Right and left are only for the purposes of routing the the correct wires.

 

Here is the diagram for 6DJ8 tubes:

 

9 Pin socket                                 Left LD socket                    Right LD socket

 

1 plate triode 1                                     5

2 grid triode   1                                     1

3 cathode triode 1                                 2

4 heater                                                                                           3

5 heater                                                                                           4

6 plate triode 2                                                                                 5

7 grid triode 2                                                                                   1

8 cathode triode 2                                                                             2

9 Shield tied to pin 8 at the socket (Use short wire to connect terminals 8&9 together on the breadboard only.)

 

As you can see, the changes from 12AX7 to 6DJ8 only involve one of the adapters. If you want to change the wiring, only do it at the breadboard terminals; leave the adapter connections where they are.

 

With the 12AX7 setup you can buy a plug in adapter to play octal 6SL7 and 6SN7 tubes. The 6SN7 draws more current than the Little Dot can handle, so you will need an external power adapter such as an old laptop adapter and a voltage regulator.

 

I have tried to be very thorough in showing how to build an adapter and how easy it really is when you have the right parts. This is a first draft, and there may be errors and omissions. Please submit your comments and suggestions on how to improve this post.

 

Many thanks to AFB for coming up with the original flying tube adapter and to Gibosi for posting the diagrams and overall guidance, and to all others who have contributed and helped to enhance the Little Dot listening experience.

 

Happy tube rolling!


Edited by mordy - 12/30/13 at 10:00am
post #4508 of 10486

Hey mordy!

 

What I do is compose any long writeup that is to be posted on the web in either MS Word or OpenOffice Writer. In each program you would have autosave turned on so all you would really loose is 5 minutes of composing or editing if anything went wrong.

 

I have all my pictures named, sized and in one folder for upload after all the text is written. I just put In placeholders for the pictures like [lcd3_side_view.jpg]. Then after everything has been written and spell / grammar checked I copy all the text and paste it into the post editor of whichever site I am uploading it to. I do all text formatting in the post editor on the site, if you do it in Word most formatting will not look correct or translate properly on the web site. I replace all the picture placeholders with the images that I have uploaded, a little fine tuning and hit the preview button. If all looks good then submit your post and all should be good, you can always go back and edit it if someone picks up on and errors... :D

 

For example here is my Impression writeup I did for the Burson Conductor SL and Audeze LCD-3's I had on loan for three weeks.

http://trolldragon.wordpress.com/2013/12/01/top-of-the-line-impressions/

 

All text was composed in MS Word then copied and pasted to the Wordpress entry editor, fine tuned, pictures linked and voila a blog entry was made. Now recreating the same layout here on Head-Fi was a real PiTA as Head-Fi's editor is severely feature crippled compared to the Wordpress one. This is understandable because on a forum security against hacks is a priority.

 

The Draft function I was talking about is a feature of another forum I visit on a regular basis.

:beerchug:

post #4509 of 10486

If somebody wants to roll 12ax7 type tubes i have a spare adapter PM me if interested .

post #4510 of 10486
Quote:
Originally Posted by Audiofanboy View Post
 

Speaking of Christmas - or whichever holiday floats your boat, I don't want any trouble here lol - I got my filtering power strip a bit earlier than I expected, which is good since it'll allow me to familiarize myself with the new sound before I get all those cool tubes in a week.

 

Same product as - may his soul rest in peace - Acapella11 mentioned months back, this:

http://www.amazon.co.uk/Tacima-Conditioner-Frequency-Interference-Filter/dp/B000PS5700

 

Yes, it's cheap; yes, it only has UK sockets (I live in France, use different plugs and still bought it, so it just takes a little creativity); no, I wouldn't use it with non-220-240V AC power; but yes, it makes a COLOSSAL difference!

 

Honestly, I had expectations that it would at least make a difference with the Little Dot plugged into it - after all, removing noise from power is never bad - but it's rare that a brand new product I add to my sound chain makes a such a difference that at the very first second of listening I'm like "Oh. I see. And I was missing this all these years, huh? There must have been something wrong with my head... Is this really happening? How can this sound so good? And for £30?!? Holy ****...!!"

 

Anyway, I won't go any further since this is largely irrelevant on this thread, but I strongly urge you to get a similar product. It made enough of a difference with just the LD plugged into it, but when I added the DAC to the filtering power strip, it felt like I multiplied the price of my system by 3... You may think I'm joking or overreacting, but you all know I usually don't muck around. The difference is HUGE and makes me wonder just why it took me that long to do something about my power... It feels like I'm listening to a different system right now, and it's better than mine!

 

Lesson learned: Filter thine wall power.

 

 

Quote:
Originally Posted by Audiofanboy View Post
 

 

These are pretty close to perfect values actually, right?

 

That makes me want to try two C3G pentodes, now that we know that the cathode resistor is largely irrelevant - for all intents and purposes.

 

Hi AFB.

 

I certainly second your recommendation re. mains filter/conditioning...I would have said essential...and shame on you for not having 'cleaned up' sooner!! And don't neglect the individual equipment power leads either, folks - upgrade 'em. And when funds are flowing, get rid of those cruddy fuses and pop in some nice (gold-plated?) ones - go on, treat yourselves...just don't tell 'er indoors!

 

 

Have been drooling over Yamamoto equipment for a while now, and did like the look of the Siemens C3ms in his HA03 amp. So the 6.3V C3gs have been quietly beckoning - your interest (along with the glowing report in JAC Music) has encouraged me to bite the bullet and splash out. So you might just be partly to blame for emptying my wallet somewhat, but hopefully NOT to no avail!

 

For some reason I have this strange feeling that they might just provide the 'missing link' in my Tesla E88CCs, which at present are undefeated - given my equipment and ears/preferences - even by the likes of TFK ECC88s; Mullard E88CCs (gold pins); RCA (Amperex) 6DJ8s; Voskhod 6N23Ps ('78s, courtesy of Gibosi, and matched '73 & '74 pair), etc. etc.

The Philips group and Russians give slightly more bass slam and mid presence (even more so with the TFKs), but they are not matching the Teslas' fabulous clarity, separation, soundstage,  detail and 3-dimensionality that just gives me that 'wrap around the head' magic...for me, anyway...Another plus is that because everything is so "clean", if I want more bass all I have to do is crank up the volume, without having to wince.

 

So perhaps the C3gs might just provide the extras, without affecting all those other qualities I have come to love in the Teslas...time will tell...

(It does however seem strange to be going back to pentodes, after all we have been doing for some time now! But if it's good enough for Yamamoto........)

 

Cheers everyone, and a HAPPY NEW YEAR to you all.


Edited by hypnos1 - 12/30/13 at 1:06pm
post #4511 of 10486

Long time no seen.

 

Here i can show how my Russian tubes have advanced.

First there is 6ZH1P, second 6N2P, third 6N8S and last but not least 6N13S. Last one is not very compatible with little dot's so i made bigger adapter for it. (read whole amp)

 

Haven't had time to listen little dot for days. Building these DIY amps have kept me busy. Do not know where do i need power what two 6AS7/6080 as powertubes will deliver, but at least building amps have been fun. And when you know all the parts inside your amp, then you can try to do improvements to it. At least i have something always in my mind and i need to open my DIY amp and solder more parts.

 

I wish you all happy new year and have fun with tube rolling.

post #4512 of 10486

Hi i just received my LD 1+ and i have a problem with it all tubes that i tried they HUM i mean all tubes EF91 Ef92 and EF95 they all hum except the tube that come with it which is 6J1.that 6J1 is dead quiet even in high gain with those EF91 EF92 and EF95 in high gain they hum loud.

post #4513 of 10486
Quote:
Originally Posted by Audiofanboy View Post
 

Honestly, I had expectations that it would at least make a difference with the Little Dot plugged into it - after all, removing noise from power is never bad - but it's rare that a brand new product I add to my sound chain makes a such a difference that at the very first second of listening I'm like "Oh. I see. And I was missing this all these years, huh? There must have been something wrong with my head... Is this really happening? How can this sound so good? And for £30?!? Holy ****...!!"

 

 

£30 is quite reasonable, but unfortunately, this filtering power strip is not designed for use in the US. Does anyone have a recommendation for a similarly-priced unit suitable for 120 volt mains?

post #4514 of 10486
Quote:
Originally Posted by gibosi View Post
 

 

£30 is quite reasonable, but unfortunately, this filtering power strip is not designed for use in the US. Does anyone have a recommendation for a similarly-priced unit suitable for 120 volt mains?

When Audiofanboy purchased is power bar i checked around a bit for something similar didnt find anything is that price range the cheapest i found was around $270.00 and it went into the thousands 

this EMI FILTER   http://www.partsconnexion.com/prod_pdf/ftech_76110.pdf

post #4515 of 10486

Hi Artsi,

 

Is the 6N13s similar to the 6080 tube which is used in the LD MK9 ?

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